Starting to look ahead to the upcoming OnTap 7. I'm very excited about the new aggregates and flexvols. What criteria should one use in determining the number of aggregates to create? For example, FAS960 with 6ea DS14Mk2 shelves filled with 144GB FC drives. Would it be better to create one huge aggregate or several smaller aggregates? From my perspective, I see no practical use for Tradional volumes after upgrading to OnTap 7 and would like to convert to flexvols, but was wondering if anyone with any experience with any of the OnTap 7 RC's could provide feedback on this.
Thanks in advance.
William> Starting to look ahead to the upcoming OnTap 7. I'm very William> excited about the new aggregates and flexvols. What criteria William> should one use in determining the number of aggregates to William> create? For example, FAS960 with 6ea DS14Mk2 shelves filled William> with 144GB FC drives. Would it be better to create one huge William> aggregate or several smaller aggregates? From my William> perspective, I see no practical use for Tradional volumes William> after upgrading to OnTap 7 and would like to convert to William> flexvols, but was wondering if anyone with any experience William> with any of the OnTap 7 RC's could provide feedback on this.
From my reading of the documents on the NetApp web site, it looks like you'd just want to create a single large aggregate, and put all your volumes on there.
An aggregate can have multiple raid groups in it, and they recommend that you add disks to aggregates in raid group chunks. So, if you assume that a RG (Raid Group) is 14 disks in DP mode, you'd have one aggregate with 6 RGs in it. They recommend that you put as many disks into one aggregate as you can, since otherwise you could be disk bound.
Then you'd have one FlexVol vol0 (shrunk down) and however many FlexVols you wanted/needed for you data. Max of 200 FlexVols per filer though, so you'll probably want FlexVols and qtrees still. Upto 4,995 qtrees per Vol or FlexVol.
Since Vols/FlexVols cannot span aggregates, creating multiple aggregates doesn't seem to be a win at all.
I haven't touched OnTap 7G yet, but we'll be getting it soon I hope.
John
William, you might want to read this whitepaper:
http://www.netapp.com/tech_library/ftp/3356.pdf
which describes OnTap 7G (the marketing name for 7.x) and has several best practices listed for aggregates and flexVolumes.
as John suggests, you want to make aggregates as big as (reasonably) possible, within the configuration rules and best practices. things like: - there are max (raw) limits on aggregate size, just like there are on traditional volumes. the on-line system configuration guide doesn't list them yet, so I don't know where the limits are. - don't mix different drive sizes in the same aggregate - don't mix different drive speeds (10K, 15K) in the same aggregate - don't mix different shelf speeds (1G, 2G) in the same aggregate - make full raid groups, each one max size. - use Raid_DP - let OnTap pick the drives to assign to raid groups, rather than doing it "by hand". use to be, on nearstore especially, you had to hand-craft raid groups to get performance and protection; Ontap is smarter about hardware topology now, and seems to go a good job at this.
we're testing 7.0 RC on an old f87, which is fine for learning the software, tough for experimenting with large aggregates...
for your example, 6 shelves of the same type, with drives of the same type and speed, you can make one big aggregate using raid_dp, raid-group size 16, and get 5 raid groups and 4 spares.
-skottie
John Stoffel wrote:
William> Starting to look ahead to the upcoming OnTap 7. I'm very William> excited about the new aggregates and flexvols. What criteria William> should one use in determining the number of aggregates to William> create? For example, FAS960 with 6ea DS14Mk2 shelves filled William> with 144GB FC drives. Would it be better to create one huge William> aggregate or several smaller aggregates? From my William> perspective, I see no practical use for Tradional volumes William> after upgrading to OnTap 7 and would like to convert to William> flexvols, but was wondering if anyone with any experience William> with any of the OnTap 7 RC's could provide feedback on this.
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Holland, William L -
John Stoffel -
Skottie Miller